Most halflings have not permanent homeland - they are merchants that ply the waterways on their river barges. That said, those families that use the Elsir River would rarely leave the Elsir Vale. Your easiest option is to come from there. (See the Region Page in the links).

Nicko's PC is also a halfling, so perhaps you would like to tie BGs together?

“It is amazing what you can accomplish if you do not care who gets the credit.” – Harry S. Truman